Police in Yemen have clashed with demonstrators on a second day of protest over a proposed sales tax rise.

In Taiz, about 250 kilometres south of the capital, Sanaa, as many as nine people are reported to have been injured and another 10 detained.

Reports say another two people were injured in clashes in the city of al-Hadida, west of Sanaa.

Opposition parties say the tax would increase pressure on the poor and blame corruption for Yemen's economic woes.

Protests in the capital ended peacefully.

On Monday, approximately 15 people were reported to have been detained during a demonstration in the Red Sea city of Hudeida which erupted when shops closed to protest against the introduction of the tax.